How do you add and subtract #3x^2 + 2x - 5# and #-4 + 7x^2#? Algebra Polynomials and Factoring Addition and Subtraction of Polynomials 1 Answer George C. Jun 7, 2015 Addition: #(3x^2+2x-5)+(-4+7x^2)# #=3x^2+2x-5-4+7x^2# #=3x^2+7x^2+2x-5-4# #=(3+7)x^2+2x-9# #=10x^2+2x-9# Subtraction: #(3x^2+2x-5)-(-4+7x^2)# #=3x^2+2x-5+4-7x^2# #=3x^2-7x^2+2x-5+4# #=(3-7)x^2+2x-1# #=-4x^2+2x-1# Answer link Related questions How do you add two polynomials? How do you subtract two polynomials? How do you add and simplify #3x^2-4x+7# and #2x^3-4x^2-6x+5#? How do you subtract #5b^2-2a^2# from #4a^2-8ab-9b^2#? How do you simplify #(6.9a^2-2.3b^2+2ab)+(3.1a-2.5b^2+b)#? How do you simplify #(-t+15t^2)-(5t^2+2t-9)#? How do you subtract #(-5m^2-m)-(3m^2+4m-5)#? How do you add two polynomials if they don't have like terms? How do you simplify #(3a+4b)-(-6a-3b)#? How do you subtract #(x^2-8x+7)-(6x^2+7x-3)#? See all questions in Addition and Subtraction of Polynomials Impact of this question 2460 views around the world You can reuse this answer Creative Commons License